This invention relates to off road vehicles having air cleaners or pre-cleaners coupled with the vehicle""s internal combustion engine.
It is known to provide off road work vehicles such as loader backhoes with large air intake pipes that extend upwardly from the vehicle hood. These vehicles generate a large amount of dust and airborne debris as the wheels contact the ground. The air proximate the ground and tires tends to contain large quantities of dirt and debris. Also, the engine cooling fan located proximate the engine within the engine enclosure tends to generate dust and airborne debris. The pipes extend high above the hood so that relatively clean air can be pulled into the pipe. These pipes often have the disadvantage of being positioned directly in front of the vehicle operator station, and therefore can block or obstruct the operator""s forward view from the operator station.
It is also known to provide off road work vehicles with an air intake pipe having a pre-cleaner mounted to the top of the pipe. One type of pre-cleaner includes propeller blades that rotate as air is drawn through the pre-cleaner for use by the engine. Rotation of the blades imparts a centrifugal force to the air and debris. The airborne debris is heavier than the surrounding air, and the centrifugal force imparted to the debris propels the debris outwardly through a debris outlet. The air is thereby cleaned of heavy debris and airborne dirt, and the air remaining within the pre-cleaner is pulled downwardly through the intake pipe for use by the internal combustion engine. Air intake pipes having pre-cleaners mounted on the top of the intake pipe also have the disadvantage of blocking the seated operator""s view from within the operator station.
It would therefore be desirable to provide an air intake mechanism that would generally not obstruct the view of the operator during operation of an off road work vehicle. It would also be desirable for such a mechanism to direct relatively clean air toward the vehicle""s internal combustion engine.
The preferred embodiment of the present invention provides an off road work vehicle having an internal combustion engine positioned within an engine enclosure. An air pre-cleaner is fixed with the engine enclosure and serves to direct cleaned air to the engine to facilitate combustion within the engine. The air pre-cleaner includes fan blades which rotate to propel airborne debris radially outwardly with centrifugal force so that relatively heavy airborne debris is expelled from the pre-cleaner through a debris outlet near the upper portion of the air cleaner. The debris outlet is formed in a cap of the pre-cleaner and is located above a top surface of the engine enclosure. The pre-cleaner includes an air inlet positioned beneath the debris outlet and located within the engine enclosure. The air pre-cleaner defines a clean air outlet through which cleaned air from the air pre-cleaner passes to the engine. Ducts positioned within the engine enclosure direct air toward the air inlet of the air pre-cleaner. A duct inlet is formed in the engine enclosure for directing air from the exterior of the engine enclosure into the duct.